HP Integrity Virtual Machines 4.2: Installation, Configuration, and Administration

NOTE: The Online VM Migration feature is not supported for a guest running as a Serviceguard
node. Therefore, disable online migration for all guests that are Serviceguard nodes. For example:
# hpvmmodify -P sg_node1 -x online_migration=disabled
The Online VM Migration feature is supported with Serviceguard packaged guests. For more
details, see Section 10.4 (page 181).
10.2.5 Using the hpvminfo Command in the Guest
The hpvminfo command is part of the Integrity VM guest kit and should be installed on all of
your guests. Use the hpvminfo -V option to display information about the guest and the current
VM Host.
The following is a shell script using the hpvminfo -M option (for machine-readable output)
that you can run on any Unix guest to show when an online migration has occurred. The script
gets the guest name (G), and the current host (H1), and then begins an infinite loop testing and
reporting if the host on which it is running has changed. Terminate the shell script with a ^C.
G=$(hpvminfo -M | awk -F : '{print $12;}')
H1=$(hpvminfo -M | awk -F : '{print $7;}')
echo $(date) $G: Current host is $H1
while true
do
H2=$(hpvminfo -M | awk -F : '{print $7;}')
if [ "$H1" != "$H2" ]; then H1=$H2; echo $(date) $G: host is now $H2; fi
done
The following is a sample output from this script:
Tue Aug 26 10:52:39 PDT 2008 vm6: Current host is host2
Tue Aug 26 10:53:36 PDT 2008 vm6: host is now host1
Tue Aug 26 10:54:28 PDT 2008 vm6: host is now host2
Tue Aug 26 10:55:19 PDT 2008 vm6: host is now host1
10.3 VM Host and Virtual Machine Configuration Considerations
This section discusses the configuration information you need for a successful migration and
how to chose which hosts and guests can participate in Online VM Migration. Effective migration
of online guests among VM Hosts depends on proper configuration of the networks and storage
connected to the VM Host and used by the online guests. The hpvmmigrate command verifies
that the source and target hosts provide the guest with symmetric accessibility to network and
storage resources. If you set up the configuration properly on both hosts before you migrate the
guest, the migration task is much easier and faster.
To migrate guests among a group of VM Host servers, the VM Hosts require common access to
storage devices, networks and virtual switch configurations. Pathnames to storage need not be
identical, however the same LUNs assigned to a guest must be presented to both the source and
the target VM Hosts. There must be equivalent access to guest storage and equivalent network
reachability on both the source and the target VM Hosts. The network on the target VM Host
must be able to make all the same network connections that can be used by the guest on the
source VM Host.
A vswitch of the same name, connected to the same network must be available on the source
and target VM Host servers. The hpvmmigrate command does connectivity checking before
migration. You can use the hpvmmigrate -w option to bypass the vswitch connectivity checks,
but only use -w if you are certain that the source and target vswitches are connected to the same
subnet. Otherwise, your guest will lose network connectivity after migrating.
For online migration, in addition to sharing the same LAN segment for normal guest connectivity,
the VM Hosts should be connected with a private 1 GbE (or faster) network for efficient VM
Host–to-VM Host communications and for secure guest memory transfer. Using NTP for time
174 Migrating Virtual Machines